Qin-Ying Qiu

Sun Yat-Sen University, Shengcheng, Guangdong, China

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Publications (6)22.11 Total impact

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    ABSTRACT: To examine how the sarcoplasmic reticulum (SR) Ca2+ content changes and the underlying mechanism in L-thyroxin-induced cardiac hypertrophy. Echocardiography was used to confirm the establishment of the cardiac hypertrophy model. The confocal microscopy and fluorescent indicator Fluo-3 was applied to examine the intracellular Ca2+ concentration ([Ca2+]i), the Ca2+ sparks, and the caffeine-induced Ca2+ transient in freshly isolated cardiac ventricular myocytes. The activity of sarcolemmal and SR Ca2+-ATPase 2a (SERCA2a) in the ventricular tissue was also measured, respectively. L-thyroxin (1 mg/kg injection for 10 d) induces left ventricular cardiac hypertrophy with normal myocardial function. The decreased caffeine-induced Ca2+ transient in the Ca2+-free solution was detected. The spontaneous Ca2+ sparks in hypertrophied myocytes occurred more frequently than in normal cells, with similar duration and spatial spread, but smaller amplitude. Then the basal [Ca2+]i increase was observed in quiescent left ventricular myocytes from hyperthyroidism rats. The activity of sarcolemmal and SR Ca2+-ATPase was decreased in the hypertrophied ventricle tissue. The results suggested that the reduced SR Ca2+ content may be associated with an increased Ca2+ leak and reduced SERCA2a activity, contributing to abnormal intracellular Ca2+ handling during hypertrophy in hyperthyroidism rats.
    Acta Pharmacologica Sinica 05/2008; 29(4):430-6. DOI:10.1111/j.1745-7254.2008.00763.x · 2.91 Impact Factor
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    ABSTRACT: The cerebrovascular remodeling is a prominent feature of hypertension and considered a major risk factor for stroke. Cerebrovascular smooth muscle cells meet volume challenge during this pathophysiological process. Our previous studies suggest that volume regulated chloride channels may be critical to the cell cycle of vascular smooth muscle cells. However, it is unknown whether the volume-regulated chloride movement is altered in hypertension. Therefore, we directly measured the concentration of intracellular chloride ([Cl(-)](i)) in rat basilar arterial smooth muscle cells isolated from control rats and rats that were made hypertensive for 1 to 12 weeks after partial renal artery constriction (2-kidney, 2-clip method) using a 6-methoxy-N-ethylquinolinium iodide fluorescence probe. The [Cl(-)](i) in isotonic solution showed no difference in all of the groups. After hypotonic perfusion, the reduction in [Cl(-)](i) was more prominent in hypertensive cerebrovascular smooth muscle cells than in sham control cells. Genistein, a protein tyrosine kinase inhibitor, inhibited hypotonic-induced reduction in [Cl(-)](i), whereas sodium orthovanadate, a protein-tyrosine phosphatase inhibitor, enhanced hypotonic-induced reduction in [Cl(-)](i) in both groups. The percentage inhibition of reduction in [Cl(-)](i) by genistein on volume-regulated chloride movement has a positive correlation with blood pressure levels in the 2-kidney, 2-clip hypertensive group, as is the case for the percentage increase of reduction in [Cl(-)](i) by sodium orthovanadate. Antihypertensive therapy with the angiotensin-converting enzyme inhibitor captopril completely reversed abnormal volume-regulated chloride movement in hypertensive rats. We conclude that volume-regulated chloride movement is augmented in rat cerebrovascular smooth muscle cells in proportion to the severity of hypertension.
    Hypertension 07/2007; 49(6):1371-7. DOI:10.1161/HYPERTENSIONAHA.106.084657 · 6.48 Impact Factor
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    ABSTRACT: Previously, it was found that total saponins from panax notoginseng inhibited Ca2+ influx coupling to activation of alpha1-adrenoceptor. This study was designed to investigate the effects of ginsenoside-Rd from total saponins of panax notoginseng on receptor-operated (ROCC) and store-operated (SOCC) Ca2+ channels in vascular smooth muscle cells using fura-2 fluorescence, whole cell patch clamp ion channel recording, radio-ligand-receptor binding, 45Ca2+ radio-trace and organ bath techniques. It was found that ginsenoside-Rd reduced phenylephrine-induced contractile responses and Ca2+ influx in normal media without significant effect on these responses in Ca2+ -free media. Ginsenoside-Rd also decreased phenylephrine- and thapsigargin-induced inward Ca2+ currents, and attenuated thapsigargin- and 1-oleoy-2-acetyl-sn-glycerol (OAG)-induced cation entries that are coupled to ROCC and SOCC respectively. Ginsenoside-Rd failed to inhibit KCl-induced contraction of rat aortal rings and Ca2+ influx, and did not alter voltage-dependent inward Ca2+ current (VDCC) which was blocked by nifedipine. Also, ginsenoside-Rd did not change binding site and affinity of [3H]-prazosin for alpha1-adrenoceptor in the vascular plasma membrane. These results suggest that ginsenoside-Rd, as an inhibitor, remarkably inhibits Ca2+ entry through ROCC and SOCC without effects on VDCC and Ca2+ release in vascular smooth muscle cells.
    European Journal of Pharmacology 11/2006; 548(1-3):129-36. DOI:10.1016/j.ejphar.2006.08.001 · 2.53 Impact Factor
  • Guan-Lei Wang · Yan Qian · Qin-Ying Qiu · Xiu-Jian Lan · Hua He · Yong-Yuan Guan ·
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    ABSTRACT: To test the hypothesis that Cl channel blockers affect T cell proliferation through Ca2+-release-activated Ca2+ (CRAC) signaling and examine the effects of the combination of a CRAC channel blocker and a Cl channel blocker on concanavalin A (ConA; 5 mg/mL)-induced Ca2+ signaling, gene expression and cellular proliferation in human peripheral T lymphocytes. [3H]Thymidine incorporation, Fura-2 fluorescent probe, RNase protection assay, and reverse transcription-polymerase chain reaction were used. The Cl channel blocker 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS) inhibited ConA-induced Ca2+ influx, interleukin-2 mRNA expression and T lymphocyte proliferation in a concentration-dependent manner, and also enhanced the inhibitory effects of 1-[beta-[3-(4-methoxyphenyl)propoxyl]-4-methoxyphenethyl]-1H-imidazole (SK&F96365) on the above key events during T cell activation. A combination of DIDS (1 micromol/L) and SK&F96365 (1 micromol/L) significantly diminished ConA-induced ClC-3 mRNA expression by 64%, whereas DIDS(1 micromol/L) or SK&F96365 (1 micromol/L) alone decreased ConA-induced ClC-3 mRNA expression by only 16% and 9%, respectively. These results suggest that there is an interaction between CRAC-mediated Ca2+ signaling and DIDS-sensitive Cl channels during ConA-induced T cell activation and proliferation. Moreover, the DIDS-sensitive Cl channels may be related to the ClC-3 Cl channels.
    Acta Pharmacologica Sinica 04/2006; 27(4):437-46. DOI:10.1111/j.1745-7254.2006.00297.x · 2.91 Impact Factor
  • Jia-Guo Zhou · Qin-Ying Qiu · Zheng Zhang · Yu-Jie Liu · Yong-Yuan Guan ·
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    ABSTRACT: It is generally thought that receptor-operated Ca2+ entry is related to store-operated or capacitative Ca2+ entry mechanism. Recent evidence suggests that non-capacitative Ca2+ entry pathways are also involved in receptor activated Ca2+ influx in many different kinds of cells. In this study, we studied whether alpha1-adrenoreceptor (alpha1-AR)-activated Ca2+ entry is coupled to both capacitative and non-capacitative pathways in A10 vascular smooth muscle cells by fura-2 fluorescence probe and conventional whole-cell patch clamp techniques. We found that both thapsigargin (TG) and phenylephrine (Phe) induced transient increase in cytoplasmic Ca2+ concentration ([Ca2+]i) in Ca2+-free medium, and subsequent addition of Ca2+ evoked a sustained [Ca2+]i rise. When the membrane potential was held at -60 mV, both TG and Phe activated inward currents, which were inhibited by GdCl3(Gd3+), 0Na+/0Ca2+ solution and 1-{beta[3-(4-mehtoxyphenyl)propoxy]-4-methoxypheneth-yl}-1H- imidazole hydro-chloride (SK&F96365), but not by nifedipine. When Ca2+ store was depleted by TG in Ca2+-free solution, Phe failed to further evoke [Ca2+]i rise. However, when capacitative Ca2+ entry was activated by TG in the medium containing Ca2+, 10 microM Phe further increased [Ca2+]i. At the same concentration, TG activated an inward cation current, subsequent addition of Phe also further induced an inward cation current. Furthermore, the amplitudes of [Ca2+]i increase and current density induced by Phe in the presence of TG were less than that induced by Phe alone. Our results suggest that both capacitative and non-capacitative Ca2+ entry pathways are involved in Ca2+ influx induced by activation of alpha1-AR in A10 vascular smooth muscle cells.
    Life Sciences 02/2006; 78(14):1558-63. DOI:10.1016/j.lfs.2005.07.022 · 2.70 Impact Factor
  • Jia-Guo Zhou · Jing-Li Ren · Qin-Ying Qiu · Hua He · Yong-Yuan Guan ·
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    ABSTRACT: We previously found that antisense oligonucleotide specific to ClC-3 (ClC-3 antisense) prevented rat aortic smooth muscle cell proliferation, which was related to cell volume regulation. In the present study, we further characterized the regulation of intracellular Cl(-) concentrations ([Cl(-)](i)) via volume-regulated ClC-3 Cl(-) channels in an embryo rat aortic vascular smooth muscle cell line (A10 cell) and ClC-3 cDNA-transfected A10 cells (ClC-3-A10) using multiple approaches including [Cl(-)](i) measurement, whole cell patch clamp, and application of ClC-3 antisense and intracellular dialysis of an anti-ClC-3 antibody. We found that hypotonic solution decreased [Cl(-)](i) and evoked a native I(Cl.vol) in A10 cells. The responses of [Cl(-)](i) and I(Cl.vol) to hypotonic challenge were enhanced by expression of ClC-3, and inhibited by ClC-3 antisense. The currents in A10 (I(Cl.vol)) and in ClC-3-A10 cells (I(Cl.ClC-3)) were remarkably inhibited by intracellular dialysis of anti-ClC-3 antibody. Reduction in [Cl(-)](i) and activation of I(Cl.vol) and I(Cl.ClC-3) in A10 and ClC-3-A10 cells, respectively, were significantly inhibited by activation of protein kinase C (PKC) by phorbol-12,13-dibutyrate (PDBu) and inhibition of tyrosine protein kinase by genistein. Sodium orthovanadate (vanadate), a protein-tyrosine phosphatase inhibitor, however, enhanced the cell swelling-induced reduction in [Cl(-)](i), accompanied by the activation of I(Cl.vol) and I(Cl.ClC-3) in a voltage-independent manner. Our results suggest that the volume-regulated ClC-3 Cl(-) channels play important role in the regulation of [Cl(-)](i) and cell proliferation of vascular smooth muscle cells.
    Journal of Biological Chemistry 03/2005; 280(8):7301-8. DOI:10.1074/jbc.M412813200 · 4.57 Impact Factor